1. Field of the Invention
The present invention relates to a combination weighing apparatus for weighing a plurality of articles to be weighed so that a product of a predetermined weight can eventually be obtained.
2. Description of the Prior Art
Articles such as a cooked food "tsukuda-ni" or "sigure-ni" boiled down in soy that are available in supermarkets are generally sold as packed in a package containing a predetermined weight of the article. As an apparatus for dispensing the articles into packages each containing the weighed article, a combination weighing apparatus has hitherto been known in which container or trays each accommodating materials prepared in a small amount (article to be weighed) are weighed by a weighing machine while being successively transported past a weighing station towards a collecting station by means of a transport conveyor system and are, after having been weighed and then transported to the collecting station, subjected to a combination calculation by means of a combination calculating means to select a combination of the materials of a weight equal or approximate to a target weight within a predetermined weight allowance, and in which only the containers or trays which have accommodated the successively selected combinations of the materials are subsequently discharged and recovered from the transport conveyor system.
In such case, respective weights of the articles to be weighed, which have been weighed by the weighing machine, are successively transported to the combination weighing apparatus for combination calculation in the order in which the articles to be weighed have been placed on the transport conveyor system, and the combinations of the articles are then selected and discharged.
In the prior art combination weighing apparatus of the type discussed above, however, it often occurs that during the transportation of the articles to be weighed towards the collecting station subsequent to the weighing, one or some of the containers carrying the articles may, for example, removed or fall downward from the transport conveyor system or may be jammed in machine components of the combination weighing apparatus and, therefore, the necessity may consequently occur to remove such one or some of the containers. Once this trouble happens, the order of the containers being transported may change and the sequence of weight data supplied according to the order of successive transportation will not match with the order of the articles to be weighed that are successively transported as carried by the respective containers. For this reason, the combination calculation need be interrupted temporarily so that the weight values of the respective articles to be weighed can be put in order. Thus, with the prior art combination weighing apparatus, a trouble shooting necessitated subsequent to change of the order of transportation is complicated and time-consuming.